Recently, stereo display has become a development trend of display field. Especially, a stereo liquid crystal display (LCD) not only has advantages of a liquid crystal display, such as ultrathin, power-saving, but also may allow a viewer to percept distances of respective objects in an image, and thereby to obtain more full and real information. Therefore, the stereo display has broad application prospect.
The existing stereo LCDs, which operate by means of Polarized Filter, parallax barrier, or Lenticular lens plate, utilize a principle about human eyes' binocular disparity. That is, there is a distance of about 65 mm between two eyes of a human. Thus, the left eye and the right eye will see two slightly different 2D images because of the position difference of two eyes. These two different images are synthesized by the brain of the human, resulting in a stereo image with a depth.
A stereo display technology, referred as Active Retarder (AR), is popular in the art, since it advantageously does not decrease resolution and the glasses thereof are light and portable. An AR 3D display device, as shown in FIG. 2, comprises a display panel 100 and an AR 200 disposed on the display panel 100. The AR, as shown in FIG. 1, comprises an upper substrate 7, a lower substrate 1 and a liquid crystal layer 4 disposed therebetween. A common electrode 6 and an upper alignment layer 5 are provided on the upper layer 7, and a lower alignment layer 3 and several strip-shaped signal electrodes 2 are provided on the lower substrate 1. The AR may be divided into several strip-shaped regions corresponding to the strip-shaped signal electrodes 2, the signal voltage for each strip-shaped region may be controlled independently. When an electric field is applied, LC molecules of the liquid crystal layer are on twisted state and the light passing through the LC layer is twisted 90 degrees. When no electric field is applied, the LC molecules are aligned in the direction perpendicular to the upper substrate surface, and therefore, the polarized direction of the light passing through the LC layer is not changed. The liquid crystal display panel may be other types except for TN type, such as, OCB type, and the application principles are similar. Each strip-shaped region of the AR corresponds to several sub-pixels on the display panel, as shown in FIG. 2.
The prior art driving method for a 3d display with an AR is as following. During the first time period, no electric field is applied to all of ARs 200, the display panel 100 displays a left eye image, and the polarized direction is modulated as left-handed polarized direction. During the second time period, the display panel 100 is line-by-line inputted with the right eye image from the top down (from left to right in FIG. 3), and then an electric field is applied to the first strip-shaped region of the AR 200 so that the polarized direction of exiting light of this area is modulated as right-handed polarized direction and the several sub-pixels corresponding to the first strip will be seen by the right eye of a viewer. In this way, the display panel is controlled to display a right eye image line-by-line, and an electric field is applied to the corresponding AR line by line, and the polarized direction of the exiting light from corresponding sub-pixels is modulated as right-handed polarized light. Thus, left and right eyes of the viewer may both see all pixels of the display so as to achieve a full resolution. In contrast, the manner using a film-type patterned retarder technology will cause resolution decreased by one half. However, the driving method may increase flicking of 3D display, and thus may cause the human eyes to feel tired and other physiological discomforts.
The principle of increasing the flicking of the 3D display is shown in FIG. 3. The AR controls the polarized direction of the exiting light so that a left eye image is scanned first, and then a right eye image is scanned line-by-line from the top down. When the display of that frame is completed, a left eye image is scanned line-by-line from the top down. Since the viewer will see the image through polarizing glasses, the lightness received by a single eye of the viewer is proportional to the area of the image seen by the eye. The dashed line in FIG. 3 represents the varying trend of the lightness received by the left eye as time varies; and the real line represents the varying trend of the lightness received by the right eye. It is apparent from FIG. 3 that the lightness varies greatly in the display process, and thus resulting in flicking, causing the viewer to feel discomfortable.